The Mayo Alzheimer's Disease Research Center (ADRC) operates in Rochester, MN, and Jacksonville, FL, recruiting and following subjects for the purpose of pursuing the primary themes of the center. The Clinical Core of the ADRC is the focal point of activity of the Center and will recruit and characterize subjects for all three research projects. The specific aims of the Core are 1) to recruit and follow subjects on the AD degenerative spectrum with a particular focus on early disease (MCI), 2) to recruit African-American subjects on the AD degenerative spectrum with special focus on early disease (MCI), 3) to recruit and follow subjects with non-AD dementia, e.g., frontotemporal dementia, dementia with Lewy bodies, corticobasal degeneration, 4) to obtain and analyze MRI studies on selected groups of subjects, e.g., normaI-MCI-AD subjects, and provide frontotemporal dementia subjects for Project 1, and 5) to supply subjects for the Neuropathology Core and Projects 1, 2 and 3 of the ADRC. In Rochester, cognitively-impaired (CI) and normal control (NC) subjects will be derived from community and regional resources. In Jacksonville, the CI and NC African-American subjects, as well as indigent CI subjects, will be derived from community resources. The NC and CI subjects will be evaluated and followed in an identical fashion between the two sites, and all of the data will be entered into a common database. The subjects will be screened for participation in Projects 1, 2, and 3 as well as several other ongoing and future studies. The concerns and suggestions from the summary statement for the prior ADRC grant application and from the External Advisory Committee have been addressed. Most of the activities will be a continuation of current practices in the Mayo ADRC, with emphases on the primary themes of the center: the clinical, genetic, neuropsychological, neuroradiologic, and neuropathologic characterization of Caucasian and African-American subjects with normal cognition, mild cognitive impairment, and Alzheimer's disease of mild to moderate severity, and the characterization of subjects with non-AD dementias.